Field of the Disclosure
The technology of the disclosure relates to ways to facilitate the provision of location based information to wireless client devices in a distributed communication system.
Technical Background
Wireless communication is rapidly growing, with increasing demands for high-speed mobile data communication. So-called “wireless fidelity” or “WiFi” systems and wireless local area networks (WLANs) are being deployed in many different types of areas (e.g., coffee shops, airports, libraries, etc.). Distributed communications or antenna systems communicate with wireless devices called “clients,” “client devices,” or “wireless client devices,” which must reside within the wireless range or “cell coverage area” to communicate with an access point device. Distributed antenna systems are particularly useful when deployed inside buildings or other indoor environments where client devices may not otherwise be able to receive radio frequency (RF) signals from a source.
One approach to deploying a distributed communications system involves the use of RF antenna coverage areas, or “antenna coverage areas.” Antenna coverage areas can have a relatively short range from a few meters up to twenty meters. Combining a number of access point devices creates an array of antenna coverage areas. Because the antenna coverage areas each cover small areas, there are typically only a few users per antenna coverage area. This minimizes the amount of bandwidth shared among users.
One type of distributed communications system for creating antenna coverage areas, called “Radio-over-Fiber” or “RoF,” utilizes RF signals sent over optical fibers. Such systems can include a head-end station optically coupled to multiple remote antenna units that each provide antenna coverage areas. The remote antenna units each include RF transceivers coupled to an antenna to transmit RF signals wirelessly, wherein the remote antenna units are coupled to the head-end station via optical fiber links. The RF transceivers in the remote antenna units are transparent to the RF signals, and convert incoming optical RF signals from the optical fiber link to electrical RF signals via optical-to-electrical (O/E) converters, which are then passed to the RF transceiver. The transceiver converts the electrical RF signals to electromagnetic signals via antennas coupled to the RF transceiver provided in the remote antenna units. The antennas also receive electromagnetic signals from clients in the antenna coverage area and convert them to electrical RF signals (i.e., electrical RF signals in wire). The remote antenna units then convert the electrical RF signals via electrical-to-optical (E/O) converters. The optical RF signals are then sent to the head-end station via the optical fiber link.
It may be desired to provide such optical fiber-based distributed communications systems indoors, such as inside a building or other facility, to provide indoor wireless communication for clients. Other services may be negatively affected or not possible due to the indoor environment. For example, it may be desired or required to provide localization services for a client, such as emergency 911 (E911) services as an example. If the client is located indoors, techniques such as global positioning services (GPS) may not be effective at providing or determining the location of the client. Further, triangulation and/or trilateration techniques from the outside network may not be able to determine the location of the client.